Not only did Ford never build a Boss anything in a convertible body style, nor did Ford build a Boss 351 in 1970. Yet all the elements were there that year, leading at least one Mustang enthusiast to build this what-if one-of-none 1970 Ford Mustang Boss 351 convertible for sale on Hemmings.com. From the seller’s description:

It was built only 4 years ago on a 1970 Mustang Convertible frame with sub-frame connectors and 3-stage stiffening. It has the ’70 rocker panels, the ’67-’68 one-piece seat frame, and ’65-’66 steel plate underneath the seats to make the ride extra tight. It also features a Fastback-style rear end/quarters, which gives this car 3″ more width than a standard 70 convertible.

The Boss 351 badging, front/rear spoiler, hood scoop, etc. were also added for Boss 351 flare plus the original convertible top that came with the car. Under the hood, this Mustang features a 351 Cleveland V-8, mildly ported 2-bbl with Cleveland heads, Boss valve train with screw-in studs and guide plates, stainless steel roller rockers, solid lifter comp cam (similar to Boss 351 specs), double roller timing chain, Clevite 77 bearings, 3.91 9″ rear end, and all ARP hardware. The interior is new and it has a stock Hurst shifter 4-speed.

” It performs incredibly well, giving you all the benefits of a Boss 351 with a hair-blowing convertible top”

Apparently the seller has never driven a Boss anything because with a 2bbl on top, it aint no Boss! They even put 3.91 gears in it according the the sellers web site.
I’m guessing somebody had a Mustang convertible with rusted quarter panels and put fastback quarters on it. After that, it was easy to put on a repo shaker hood & a stripe set.
Why somebody would rebuild a 351C and only put a 2bbl on it is beyond my level of thinking! Sure it’s an easy 4bbl conversion but for $46K for a “one of none”, I’d expect more.

“Fastback-style rear end/quarters”!? If I were to put this much time, money, and effort into altering a 1960s-era antique, I wouldn’t try to create a fake collector car; I’d create the ideal 1965-1967 Pontiac full-size wagon, one with all modern active and passive safety equipment, R134 a/c, modern tires and drivetrain, etc.

(We had a fully optioned ’67 Executive Safari wagon in our family, an ex-demonstrator, when I was a kid; it had the options that were new or revised for that year – automatic temp control, 8-track player, cruise control – as well as vinyl roof, wind deflector, cornering lights, etc. About the only missing option was power vent windows. Before that we had a ’65 Bonneville Safari.)

I don’t get it. Why pay 47 large for a fake, when you can get a legit Mustang for less? A quick scan of the Hemmings classifieds and I saw that you can almost buy 4 nice legit Mustangs for that kind of money. It’s fake…a nice fake maybe..but still fake.

You won’t touch a Boss anything for that money. I saw a parts car at carlisle that they wanted over 20K becuase it used to be a Boss. That price is very much in line with other restored converts from 69/70. He built his way and if someone else likes it they’ll have a unique Mustang. something that can be very hard to do with so many cars out there.
I’d be willing to bet that they were talking about 2bbl hreads not carb.@ bbls are better for street use.

Back in the day Car and Driver had a ’69 Boss 302 convertible in hot yellow on their cover. Reason I remember is that I had and still have a ……… for bright yellow cars. The cover car stuck with me even after my wife bought a Silver Jade color ’69 Boss 302. I did lower myself to drive a silver jade car in gymnkanas even though I would have preferred bright yellow. Grabber Blue rag top would be a bad ride even if a sort of Frankenmonster. Great!

The door hinges make me think this is still a work in progress. As Fred said lose the stripes and I’ll add lose the hood locks and the rear spoiler: that was such a good idea to graft on fastback back end, but the shape of the 70 FB already has a spoiler lip. I’d also add a Shelby style conv. Roll bar and either the full or small shifter console to dress up the interior.

I can’t say how much I like the idea of changing the back – that’s something Ford should have done instead of using the wimpy coupe rear clip on the convertibles.